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1.
铅锌矿床中微量元素的富集特征、富集机制及对矿床成因指示是当前矿床学研究的热点之一。对铅锌矿床微量元素富
集及关键测试技术研究新进展进行了综述,指出:①富集微量元素的铅锌矿床不仅分布于古陆边缘,造山带也是有利的构造背景;
②不同成因类型铅锌矿床所富集的微量元素种类和含量不同,元素组合、含量及比值可以指示矿床成因;③微量元素以类质同象、
固熔体、微细矿物包裹体形式甚至是独立矿物形式存在于闪锌矿和方铅矿中,富集过程受扩散速率、结晶温度、氧化还原条件、硫
逸度、成矿物质和成矿流体等物理化学条件控制;④硫化物LA-ICP-MS微区分析能精确测定硫化物中微量元素的含量,了解其赋
存状态,可为铅锌矿床成因研究提供微观证据。最后指出微量元素研究过程中要加强LA-ICP-MS原位微区测试技术的应用,并
与宏观矿床地质特征研究相结合。   相似文献   

2.
冀中坳陷发育大量隐伏玄武质岩石,尤其是坳陷北部的廊固凹陷和霸县凹陷,岩石类型以玄武岩为主,辉绿岩次之,凝
灰岩分布较少,火山角砾岩极少。通过岩心、镜下薄片及铸体薄片观察,主量和微量元素测试分析,表明该区火成岩为碱性玄武岩
和拉斑玄武岩系列;REE配分曲线呈轻稀土元素富集型,Eu异常不明显;火成岩微量元素原始地幔标准化曲线呈强不相容元素富
集。该区玄武岩的喷发环境为水下喷发;火成岩微量元素构造环境判别图解、岩石组合、岩石系列、稀土元素和微量元素特征表明
该区火成岩形成于板内大陆裂谷构造环境。通过冀中坳陷玄武岩与邻区对比发现,冀中坳陷及邻区玄武岩岩浆活动具有随时代
变化往北迁移的趋势,SiO2含量显示从南往北略为增加的趋势,北部稀土元素总量变化范围相对较大,轻稀土元素富集程度较南
部低。   相似文献   

3.
铝土矿矿床中普遍含有不同比例的鲕状矿石,但目前对这些鲕粒的成因及其与成矿作用相互关系的了解相对有限。对
贵州务正道地区铝土矿矿床中典型鲕状矿石中鲕粒进行了微区原位主量元素电子探针分析(EPMA)和激光剥蚀等离子体质谱
(LA-ICP-MS)主量和微量元素分析,并与共存基质的元素组成进行了对比。研究表明,鲕粒的形成时间晚于基质,地表化学风化
作用本身并不能导致铝土矿的形成;鲕粒的形成发生于强氧化和高酸度的环境,其成因被解释为在海进过程中在地层中一定的深
度条件下形成了以黄铁矿为主的硫化物矿物,随后的海退作用过程导致硫化物蚀变并形成强酸环境,使得成矿元素Al相对于杂
质元素(Si、Fe)发生相对富集,且该过程具有多期次振荡重复的特点。铝土矿形成是热带湿热气候条件下周期性海进-海退循环
与长期的大陆古隆起区平坦海岸地形相互耦合的结果。   相似文献   

4.
巴西卡拉加斯(Carajás)地区是世界上最著名的、矿床类型最丰富、资源最富集的成矿带之一,其氧化铁型铜-金矿床非
常典型,矿床规模巨大,找矿前景广阔。在对其进行调查研究基础上,结合前人大量的资料对其成矿地质背景、矿床特征、矿床成
因和成矿作用进行了综合总结。卡拉加斯地区的氧化铁型铜-金(IOCG)矿床的产出环境为岩石圈地幔边缘古老的俯冲带内,卡拉
加斯克拉通盆地或裂谷裂带中,成矿作用与新太古代Itacaiúnas超群下部的火山岩-火山沉积岩系(2.75Ga)和新太古代晚期的
A 型花岗岩(2.57Ga)及卡拉加斯断层带密切相关,Cu-Au-U矿体特征、成矿元素组合、成矿流体和稳定同位素组成等表现为典型
的IOCG型矿床。   相似文献   

5.
从区域成矿地质背景和主要矿床地质入手,分析了铁矿的主要控矿因素,认为区内铁矿床受地层、褶皱构造和同生断裂
构造、岩相古地理等因素制约。地层和岩相古地理因素控制了整个矿带的展布和矿床的分布,褶皱构造和同生断裂构造控制了矿
体的形态和规模。锆石LA-ICP-MSU-Pb同位素测年及矿石和围岩稀土元素地球化学特征分析结果显示,老并矿区布伦阔勒群
内长英质片岩形成年龄晚于(532±3.9)Ma;区内铁矿床的矿石和赋矿围岩具有相似的稀土元素特征和变化曲线,总体具有轻稀土
富集、重稀土亏损、呈右倾斜型特征,表明二者的物质来源具有同源性。指出了古元古界布伦阔勒群第二岩性段地层、火山沉积盆
地边缘以及背斜转折端和向斜核部是区内铁矿今后找矿的重要方向。   相似文献   

6.
选取一个含金采样剖面,对旧房梁金矿床的成矿流体性质和成矿物质来源进行了探讨。研究结果表明,旧房梁金矿床产于陕西勉略宁三角地区中新元古界碧口群,矿体的分布和产状受地层岩性和韧性剪切带的强烈控制,矿床成因类型为绿岩型金矿床。对矿石及其顶底板围岩的主微量元素和稀土元素地球化学特征及其成矿作用的研究表明:与Au含量正相关性较好的元素有Ag、Hg、Bi、Mo;在成矿过程中,矿石和围岩的Al2O3、TFe2O3及高场强元素含量较稳定;大离子亲石元素含量在矿石及矿体底板围岩中相对亏损,在矿体顶板围岩中富集;亲硫元素含量表现较为复杂,Pb含量在矿体顶板围岩及氧化矿石中富集,Mo、Hg含量在矿石中普遍升高;同时伴随岩石质量的亏损;稀土元素配分模式显示矿石及近矿围岩相对于远矿围岩具有正Ce异常和负Eu异常的特征。上述特征均表明成矿流体具有高温还原性的特点。结合矿床流体包裹体和硫同位素等特征,认为该矿床的成矿物质来源可能与碧口群地层有关,其成矿过程可能与澄江期在区内广泛形成的NNE向韧性剪切变形有关,构造矿化蚀变对围岩物质组分具一定继承性和差异性。   相似文献   

7.
德工牛场铜多金属矿床是位于甘孜－理塘结合带南段的一处斑岩型矿床,矿区与成矿关系最为密切的斑岩体为花岗闪长斑岩.该岩体与甘孜－理塘洋演化以及与斑岩型矿床间的关系是值得深入研究的课题.对矿区花岗闪长斑岩进行了地球化学研究,结果表明:花岗闪长斑岩具有高硅(w(SiO２)６６．３５％~７１．８６％)、高碱(w(K２O＋Na２O)３．６３％~７．０８％)、高钾(w(K２O)３．１１％~４．５７％)和过铝质(A/CNK０．９６~１．４９)等特征,里特曼组合指数σ 为０．５６~１．７４;稀土元素总量偏少(w(ΣREE)１１１．５６×１０－６~１２１．００×１０－６),轻重稀土元素分馏明显((La/Yb)N６．６３~９．５１);相对富集 Rb、K、La等大离子亲石元素(LILE)及高场强元素(HFSE)Th、U,相对亏损 Nb、Ta、P、Ti等高场强元素及部分大离子亲石元素(如 Ba、Sr);Fe２O３/FeO 比值平均为１．１１.综合地球化学特征表明,德工牛场花岗闪长斑岩为高钾钙碱性过铝质I型花岗岩,是典型的壳幔混源成因类型,具有岛弧花岗岩的特征;结合地质年龄资料(２１６Ma)与区域构造演化特征,判定其为印支末期甘孜－理塘洋向西侧中咱地块俯冲时在强烈的岩浆活动
中形成,矿床的花岗闪长斑岩在成岩构造事件与成矿岩石特征方面与义敦岛弧内典型斑岩型矿床的斑岩具有高度的相似性.   相似文献   

8.
该文对南秦岭龙王洞地区中生代云峰寨单元花岗岩的主量元素特征、微量元素特征及稀土元素特征进行分析研究,对该岩体进行较为全面的地球化学特征总结。研究表明:云峰寨单元花岗岩属于碱性过铝质A型花岗岩,形成于高温、贫水、高压的相对还原环境。花岗岩成因以地壳作用为主,花岗岩中稀土元素总体富集且分馏程度较高,轻稀土元素较重稀土元素富集且分馏明显。花岗岩为主动就位机制,是在早燕山期造山垮塌阶段的张性构造环境时期产生,与陆壳增厚、地幔物质减压隆升密切相关。  相似文献   

9.
稻城贡巴纳岩体位于义敦岛弧碰撞造山带的南东侧。采用LA-ICP-MS的方法研究了贡巴纳岩体,结果表明岩体锆石
LA-ICP-MSU-Pb表面年龄为(226.7±2.8)Ma,是印支期岩浆活动的产物。岩性组合复杂,在岩相学特征上,呈浅灰-灰白色,
暗色矿物含量低,并出现褐帘石等富铝矿物。岩石地球化学特征显示:高w(SiO2)=71.24%~73.86%,低MgO、FeOT、CaO,
ALK=6.47%~6.86%,A/CNK=1.04~1.07,δ=1.36~1.57,AR=4.43~4.90,属于高钾钙碱性系列过铝质花岗岩。相对富
集大离子亲石元素,贫化高场强元素;Rb/Sr=0.71~0.88,w(ΣREE)=159.3×10-6~190×10-6,轻稀土元素相对富集,轻重
稀土元素的分馏比值较高La/Yb=12.87~16.54,δEu=0.16~0.18,总体表现为右倾型,显示与Ⅰ型花岗岩的特征相似。根据花
岗岩的R1-R2,Nb-Y构造环境判别图解及区域构造演化史研究,认为该岩体形成于同碰撞构造环境,其形成与义敦岛弧带俯冲
碰撞造山活动有关,即三江古特提斯洋闭合事件对接时间为三叠纪。   相似文献   

10.
207铀矿床位于甘肃省龙首山成矿带西部,区内地质构造复杂,岩浆活动强烈。矿区出露地层主要为古元古界龙首山群
(Pt1)和下石炭统南洼顶组(C1n);出露岩体主要为中条期伟晶状白岗岩,其副矿物特征具有华南改造型产铀花岗岩的特点。区域
构造线呈北西-南东向。207铀矿床具有“岩体型”矿化特征,含矿主岩伟晶状白岗岩发生全岩矿化,矿体多呈脉状、透镜状及不规
则状;矿石类型为蚀变花岗岩型。岩体、地层和构造是铀矿化的3个重要控制因素。岩体侵位于高铀含量的龙首山群,构造上处
于古老隆起区。岩体的铀含量和铀的浸出率高,Th/U值小于3,造岩矿物黑云母的多色晕异常显著,沿断裂带发育较强的黑云母
绿泥石化及赤铁矿化(红化)。岩体较低的稀土元素总量预示其有较强的成矿能力,ΣCe/ΣY比值低对铀成矿有利。岩石的化学
评价系数x=27,岩石化学组分十分有利于铀的成矿。根据矿床成矿地质背景、铀矿化特征、控矿因素及大量资料的综合分析和研
究认为,207矿床外围铀成矿潜力巨大、找矿前景广阔,在新一轮找矿工作中应引起高度重视。   相似文献   

11.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations.  相似文献   

12.
氟、氯、溴、碘等卤族元素与人体健康的关系   总被引：1，自引：0，他引：1  
卤族元素是人体的必需元素,正常情况下成人摄入量不超过F4 mg/d、C11.7～5.1g/d、I 100～200μg/d;少年不超过F 3 mg/d,儿童I1μg/kg-d,婴儿Cl0.3～1.2 g/d.过量摄入或缺乏卤族元素,都可能导致疾病的发生.而F含量0.5～1.0mg/L、C1＜50mg/L、Br＞100μg/L、I 10～100μg/L的饮用地下水,有利于人体健康.  相似文献   

13.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these trace metals and H2S, and other oceanographic parameters were obtained in four cruises. Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S4) 2 3− and Cu(Sn4S5)3−, Zn(HS) 2 0 and ZnHS 2 − , Cd(HS) 2 0 and Ni(HS) 2 0 , respectively. The solid species controlling Fe2+ and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S−O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S−O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace metals are still in the processes of reduction and precipitation. Contribution No. 1428 from Institute of Oceanology, Academia Sinica  相似文献   

14.
Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of different dietary additives [w/w: 2% small peptides, 0.01% probiotics( Bacillus licheniformis) and 0.2% prebiotics(inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations(13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics(combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme(total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control(28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions.  相似文献   

15.
  相似文献   

16.
这里所指示的大气圈、水圈、岩石圈、生物圈以及人类的作用千变万化,从而对人类的生存造成巨大影响,构成了一个复杂的生态环境,讨论这些问题,对人类生存至关重要。  相似文献   

17.
Monthly investigatiom were made on the population of Chinese freshwater crab, Sinopotamon yangteskiense Bott, 1967 from April, 1984 to Match, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occured from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June-October. Females bearing eggs were taken from June-August, and crabs with young were found from July-October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-bom crabs become mature after 1-2 yeats. The sex ratio was approximately 1:1 in the overall population. However, the larger crabs are predominantly male. The age distribution of S. yangtsekinese was estimated from size frequency histograms. There were more adult crabs  相似文献   

18.
Monthly investigations were mae on the population of Chinese freshwater crab,Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occurred from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June–October. Females bearing eggs were taken from June–August, and crabs with young were found from July–October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-born crabs become mature after 1–2 years. The sex ratio was approximately 1∶1 in the overall population. However, the larger crabs are predominantly male. The age distribution ofS. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature crabs (over 50%) from November to May.  相似文献   

19.
从石漠化的研究现状出发,依据我国西南岩溶石山地区石漠化特征,着重分析其主要控制介质为岩性、构造、地貌、气候、岩溶、地下水、植被等自然介质因子与森林砍伐、高坡开垦等人为介质因子.石漠化是以岩溶山区脆弱的岩溶生态环境为基础,以内、外地质作用和人类恶性生态地质作用为驱动力,以资源退化和恶化为本质,基岩不断裸露,生态环境不断恶化,周而复始的恶性循环过程.提出对石漠化的研究重点是成因机理研究,对石漠化的防治应着重于对石漠化的驱动力及其主导因子的防治,阐述了治山必须先治水等防治对策与建议.  相似文献   

20.
A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawaler. Data on the concentrations of these trace metals and H2S, and other oceanographic parameters were obtained in four cruisesEquilibrium models are presented together with in situ data. The" results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and /or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S4)23- and Cu(S4S5)3-, Zn(HS)20 and ZnHS2-, Cd(HS)20 and Ni(HS)20 respectively. The solid species controlling Fe2 + and Co2+ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H2S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H2S-O2-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H2S-O2-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new s  相似文献   

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